1. Field of the Invention
The present invention relates to a coating treatment apparatus and a coating treatment method for a substrate.
2. Description of the Related Art
In a photolithography process in a manufacturing process of a semiconductor device, for example, resist coating treatment in which a resist film is formed on a semiconductor wafer (hereinafter, referred to as a “wafer”) is performed.
In this resist coating treatment, the wafer is usually held on a spin chuck, and a resist solution is supplied onto the center of the wafer with the wafer being rotated. The resist solution supplied on the center of the wafer is diffused over the entire wafer front surface by centrifugal force to form a solution film of the resist solution on the wafer font surface. Then, a so-called edge rinse is performed to remove the resist solution on a peripheral portion of the wafer (Japanese Patent Application Laid-open No. H8-107053). The edge rinse can prevent generation of particles due to the resist solution on the wafer adhering, for example, to a carrier arm and chucks of other units.
Incidentally, the edge rinse is treatment to selectively remove only the resist solution on the peripheral portion of the wafer as described above. If the edge rinse is carried out for the resist solution on the wafer which has not sufficiently dried yet, the resist solution on the center side of the wafer flows out to the peripheral portion side of the wafer during the edge rinse, failing to carry out sufficient edge rinse on the peripheral portion of the wafer. Therefore, the edge rinse is performed after the solution film of the resist solution is formed on the wafer and sufficiently dries.
However, sufficiently drying of the solution film of the resist solution formed on the wafer front surface requires a great amount of time. Actually, sufficiently drying of the solution film of the resist solution has sometimes required two minutes or more, depending on the kind of the resist solution, even though the wafer has been rotated.
As described above, in the conventional resist coating treatment, drying of the resist solution has required a great amount of time to delay the start of the edge rinse, resulting in increased total time required for the resist coating treatment and leading to reduced throughput. In addition, to increase the efficiency of wafer processing, many resist coating units need to be installed in a coating and developing treatment system in which, for example, a series of photolithography processes is sequentially performed, resulting in a larger coating and developing treatment system.